Field of the Invention
This invention generally relates to a bicycle assist unit. More specifically, the present invention relates to a bicycle assist unit that aids a in providing a drive force through the use of a motor in addition to a manual drive force for assisting riding a bicycle.
Background Information
Generally, a bicycle assist unit comprising an assist motor and a transmission. On example of a conventional bicycle assist unit is disclosed in Japanese Laid-Open Patent Publication No. 1998-194186. In this conventional bicycle assist unit, the transmission includes a planetary gear mechanism for transmitting the drive force from the motor to propel the bicycle. In this conventional transmission, the gear ratio is determined by regulating the rotation of the ring gears using a plurality of mechanical elements binding with one of a plurality of ring gears.